This summary report provides an overview of findings from the fourth annualized inventory of Delaware forests based on data collected from 2012 to 2018. Forest land area remained stable at 359,000 acres, and 51 percent of forest land is in the oak/hickory forest-type group. Forests in the State continue to mature, with 76 percent in large diameter stands and 65 percent in stands older than 60 years of age. Total live-tree net volume on timberland is 907 million cubic feet, and 92 percent of that volume is in growing-stock trees. Annual gross growth of 29 million cubic feet less annual mortality of 11 million cubic feet resulted in an annual net growth of 18 million cubic feet on timberland. Additional information on land use change, fragmentation of forest land, ownership, urban forests, species composition, stand structure, forest carbon, down woody material, regeneration, invasive plants, forest pests, tree health, and timber products output are also presented. A detailed interactive report is available at https://doi.org/10.2737/NRS-RB-129-INT, and supplemental information, including (1) tables summarizing quality assurance, (2) a core set of tabular estimates for a variety of forest resources, and (3) user and database guides for P2 and P2+ protocols, can be accessed at https://doi.org/10.2737/NRS-RB-129.